In the next generation wideband wireless communication networks, solving the problem of inter-cell interference becomes a key factor to improve user terminal (UT) throughput and the average UT throughput, and how to effectively solve the inter-cell interference faces big challenges.
Nowadays, in the Institute of Electrical and Electronics Engineers (IEEE) 802.16j, IMT-Advanced system and WINNER, methods of interference randomization, interference coordination and interference elimination are proposed to be used to solve the problem of inter-cell interference. The Long Term Evolution (LTE) system proposes, based on the above methods, dividing the coverage area of a current cell into an inner layer and outer layer according to the maximum interference level of a UT to all the adjacent cells, and employing partial power control and path loss compensation to solve the problem of inter-cell interference, wherein, the inner layer is the area with weaker inter-cell interference, and full power compensation is used to solve the problem of inter-cell interference; the outer layer is the area with stronger inter-cell interference, and partial power control and path loss compensation are applied to solve the problem of inter-cell interference.
In the LTE system, OI report is used to indicate the status of suffering interference of a physical resource block (PRB) occupied by a UT who suffers high level inter-cell interference; and load negotiation between different base stations (BS) is performed according to the OI report, so that the inter-cell interference suffered by the UT on the PRB is effectively decreased, so as to reach the purpose of coordinating the inter-cell interference.
The relative stipulation to OI report by the LTE system is as follows:
An OI value is set on each PRB, and the OI value is represented by two bits to indicate three statuses: high (00), medium (01) and low (10), which respectively represent that the statuses of the inter-cell interference suffered by the PRB is high, medium and low. Events to trigger the OI report include: over high or unacceptable Interference over Thermal (IoT), unsatisfactory uplink performance and load change in the cell.
When using the above trigger events to trigger the OI report, the OI report will be frequently triggered, thereby the load of the OI is increased, system overhead becomes very large and system operation efficiency is decreased.